The invention relates to a transport lift truck for metallurgical vessels, and particularly for steel mill converters. The truck of the invention has a lift platform with a circumference which accommodates several hoisting mechanisms on the truck frame. Also, flexibly attached pendulum rods are provided between the hoisting mechanisms and the hoisting platform.
Such lift trucks serve to transport the metallurgical vessel with worn lining which is to be replaced, to a lining station. After the new assembly, the truck returns it to the operating station. The exchange is effected, in view of the extremely heavy weight of the metallurgical vessels of several hundred tons, on horizontally installed rail tracks. Such a lift truck is also equipped with hoisting mechanisms in order to lift the metallurgical vessel from the level of the truck frame into the tipple or tilting device. The level of the tipples, in the metal treatment stations, and particularly in the steel mills, depends upon the level of the tapping vessels into which the liquid metal is tapped.
The dimensions of such tapping vessels are, in turn, determined by their capacity. Tapping vessels with a volume of up to 300 tons of steel and more are utilized. The size of the tapping vessels results in a lift of several meters for the metallurgical vessels weighing several hundred tons. In order to produce the necessary hoisting power, hoisting mechanisms are required which, distributed in sufficient number of the circumference of the hoisting platform, are able to generate the total lift power.
In metal treatment operations, such as foundries, desulfurization stands, and in steel mills, a multitude of other lift trucks are utilized besides the present kind of lift trucks, e.g. lift trucks for removable vessel parts, such as converter bottoms. Lift trucks for metallurgical vessels, or so-called converter exchange trucks, have been disclosed in German DE-PS 20 08 396; they consist essentially of a truck frame with several sets of wheels, and hoisting mechanisms arranged on the truck frame, which are connected to a hoisting platform. Also, a device has been disclosed in German DE-AS 11 41 660 with a vertical lift piston to join the converter bottom plate to a converter.
The present invention is based on the requirement of reducing the expenditure in lift trucks for metallurgical vessels. This is solved by the invention, using the lift truck mentioned initially, by providing a removable carrying device on the hoisting platform for a vessel bottom plate with the latter to be inserted in and/or removed from a metallurgical vessel. The concept of the invention thus leads directly to the combination of a lift truck as vessel exchange truck with a truck to insert the bottom plate. The invention, therefore, completely eliminates a separate truck to insert the bottom plate. Since the hoisting mechanisms of the lift truck are, without exception, dimensioned for the weight of the metallurgical vessel, it follows that the hoisting mechanisms can, without any problem, bear the weight of the various structural groups of metallurgical vessels. The combined lift truck/bottom-insert truck according to the invention incorporates a freedom of movement in the hoisting platform in any direction, so that a desired freedom of motion is given to insert the bottom portion of a vessel. Such freedom of motion is necessary to compensate for slight deviations from the structural form of metallurgical vessels which may warp during operation.
Preferably, the carrying device for the vessel bottom, according to another detail of the invention, is supported via supporting elements in recesses of the hoisting platform. The setting down of the carrying device by means of a crane into the recesses mentioned makes a further attachment of the carrying device to the hoisting platform superfluous.
In order to balance greater inaccuracies when inserting or placing vessel parts and/or vessel bottom parts which may, for example, also be caused by incorrect placement of the lift truck on the rail tracks, provision is made, furthermore, to arrange the carrying device with reference to the vessel bottom part on the hoisting platform on two crossed lines allowing for horizontal orientation and adjustment. Another adjustment feature of the invention which is useful during assembly and dismantling of entire metallurgical vessels, as well as during assembly or dismantling of vessel parts, such as vessel bottom parts, consists in providing the pendulum-seated hoisting platform with reference to the truck frame on two crossed lines allowing for horizontal orientation and adjustment. The adjusting motions may then be made in a reciprocating motion, if for each of the adjusting directions two thrust gears each are provided. In this case, the part to be moved, which may be either the hoisting platform or the carrying device, is advanced.
Additionally, in accordance herewith, the thrust gears each consist of hydraulically movable piston cylinder gears with piston rods which are each supported on vertical guides which are firmly attached to the truck frame. The vertical guides intercept here the horizontal supporting forces resulting from the thrust motion. Another improvement for the guidance of the thrust gears is achieved by attaching the guides on the casings of the hoisting mechanisms with the main axes thereof arranged vertically. Also, the friction between the vertical guides and the piston rods may be reduced by arranging rollers on the piston rods of the thrust gears, which are then supported on the vertical guides.
An exceedingly simple form of the carrying device of the invention is provided by having the carrying device for the vessel bottom part provided with a ring, with supporting cantilevered legs extending outward from the ring. Also, a ball and socket joint is provided in the center of the ring and connected to it, with the supporting plate for the vessel bottom part being joined to the latter.
An example of the invention is shown on the drawing and is explained as follows.